M16 barrel cut to 7"

[Col_Crocs]

I have a friend who cut his down to 10.5". Works fine, fairly accurate considering the drastic mod.
If you dont mind me asking, if you wanted an 11.5, why didnt you just get the BM 11.5 HBAR?

[chime]

Yes the twist rate matters. The lack of twist will cause a significant loss in velocity and accuracy esp if you have a 1/12 which I assume is what you have? Unless it's a BM which would be 1/9.
The best barrel to cut down would be a 1/7 which will give you a full spin even at 7.5".
As for the gas port, make sure your gunsmith has a lot of experience with conversions or at least chart for gas port sizes.-- shouldnt be a problem in your area.

Yup. I've got 1:12 twist rate Colt barrel. Maybe there's no problem with the conversion. U-Mar's Gunshop had already converted a lot of this "infants". I've seen one fired at 30m w/ about 4" grouping (no sign of slugs tumbling) using a surplus M16 barrel & M16 upper/lower assembly but i can't remember what ammo they are using. I think this is good enough for me. Maybe i'll just give it a try. Anyway, the barrel is just gathering dust in the toolroom.

Thanks

[lanceriley]

I have a friend who cut his down to 10.5". Works fine, fairly accurate considering the drastic mod.
If you dont mind me asking, if you wanted an 11.5, why didnt you just get the BM 11.5 HBAR?

\

In this part of the world.... barrels are expensive. I was able to get one of those surplus barrels.. didn't hurt to cut it off. after all.... xm177e2 is suppose to have small barrel not the newer thicker barrels.


yes UMARS gunshop did make the infants. but there is great loss of accuracy specially up to 50yards. 4inch group @30meters is not a good accuracy. we can do better with our pistols

[Col_Crocs]

What ammo are you using? I dont think anyone will ever feel the accuracy issue of "infants" with just basic range shooting.
One thing a friend of mine said though, from the self-defense perspective, infants with 1/12 barrels will have trouble penetrating car doors at certain distances. Whether this is true or not, I really dont know.

[lanceriley]

using military ammo m193

maybe accuracy won't be felt.... but we always like our rifles to be accurate

[chime]

What ammo are you using? I dont think anyone will ever feel the accuracy issue of "infants" with just basic range shooting.
One thing a friend of mine said though, from the self-defense perspective, infants with 1/12 barrels will have trouble penetrating car doors at certain distances. Whether this is true or not, I really dont know.

I just happen to be there when they sighted in the infant. I think they're using M193. I was told that the TP cyclic rate reducer is a must on all infants. I'm thinking of using the BCG modification done by U-Mar's to reduce the cyclic rate. I'll borrow an infant this weekend and try to test it for penetration on car door and plywood.

In this part of the world.... barrels are expensive. I was able to get one of those surplus barrels.. didn't hurt to cut it off. after all.... xm177e2 is suppose to have small barrel not the newer thicker barrels.

yes UMARS gunshop did make the infants. but there is great loss of accuracy specially up to 50yards. 4inch group @30meters is not a good accuracy. we can do better with our pistols

Yup, ur right. DPMS 14.5" barrels would go as high as $500 & 4" @ 30m is not good but there are 2 basic factors to consider when zeroing a gun, the shooter & the gun itself. I dunno which of the two to blame for the 4" group. (hehehe). One important thing to note is that it creates a perfect hole on the target so it means the bullet doesn't tumble in flight.

[lanceriley]

don't really like the infant. too short. 11.5 is good enough for me. =)

[MX5]

The barrel won't be ruined if the person doing the work knows how to do it correctly. Yes, you can buy a barrel of the desired length and maybe you'll find someone that wants the barrel that others say you should sell. The reality is that it varies from barrel to barrel, the ammo used and the intended purpose. Some of us came from an era when you couldn't just go buy parts in any configuration you wanted and we had to take quality available parts and modify them for the intended purpose. A quality part modified correctly is still a quality part and far superior to an inferior part or money foolishly.

I had a 20" Colt M16 1/12 twist barrel in VGC collecting dust in the shop for decades and nobody was interested in it. I shortened it to 8" and two weeks ago decided to check it for accuracy. With 55 grain bullets, from an unsupported prone position, it consistently printed 1.5" - 2" groups at 50 yds. There is no evidence of keyholes from 7 - 50 yds. It runs fine & this is accurate enough for the intended CQB purpose.

By the same token, I've seen stock barrels perform horribly or modified ones suffer from the inadequacies of the plumber that worked on them. You have to be careful and consider all variables. Short barreled uppers are typically are more prone to reliability problems if not set-up properly, as compared to longer barrels. As the barrel is shortened, reliability, stability and hence accuracy can become an issue depending on numerous factors. Bullet weight and rifling twist in the shorter barrels becomes even more crucial when using a suppressor

Choose wisely. YMMV

[lanceriley]

yah. I guess so I've even seen original 14.5 inch barrel that doesn't group. must be the shooter lol

[chime]

Thanks guys. Think i'll go for the 7" configuration. I'll send the barrel tomorrow to U-Mar's. I'm planning to build a Ferfrans PDW type. Wish me all the luck guys.

http://www.ferfrans.net/p_pdw.htm